Virtual Computers

Quick introduction to virtual computers: What are virtual computers? In fact, this is a quiet complex topic. It is used in many different variations. Basically, it means that you create one or more virtual computer systems on one real machine.

The advantages are a better use of the available system resources, and cost savings because you don’t need to buy and maintain a physical computer for each virtual machine you have. It is clear that buying and maintaining one powerful, physical computer is more economic than for example 12 smaller machines. Another advantage is the flexibility, which increases dramatically when you use virtual machines: Virtual computing allows you to create a new machine within minutes. You can clone existing machines, you can make snapshots so that you can go back to a previous state of your machine, etc.

The basic requirements for virtual computing are, as already said, a powerful host-computer because you have to share all system resources between your physical and all your virtual machines.

Virtual Computing is used by server administrators, so that they can host several servers on one physical machine. But also other people are using this technology. Programmers can use it in order to test their applications on the virtual machines, so that they do not need to use real computers for this. This is faster, more flexible and cheaper.

VMWare – Virtual Computing Solution

VMWare Inc. has implemented the Virtual Computing theory in its own row of products:

VMware Workstation
VMware GSX
VMware Server (Previously VMware ESX)
VMware Player

The main function is the same for all this products: You can configure, install and maintain one or multiple virtual machines. VMware Server can be downloaded free, and it has the most common functions enabled so that it should be adequate for most users’ needs.

VMware Player can also be obtained for free, but it only can run virtual machines created by another version of VMware. It’s not possible to create a VM using VMware Player.

Installing a virtual computer

In this example, I will install a virtual machine. The host computer runs on Windows XP, and the virtual machine will run Win XP also. This scenario could be useful if for example you need a second computer to test some software which you don’t want to install in a productive environment. VMware Server is used in this example.

Creating the machine

When you first launch VMware Server, you have screen like the following:

Here you click on New Virtual Machine. A wizard will appear to assist you during the set up of your new virtual machine. Confirm with Next. For the next screen, choose Typical and confirm with Next. Choose the operating system you are going to install on the machine. For this case, choose Windows XP Professional  Enter a name for the machine and the location where all the files of this machine will be stored.

Then you are prompted for the network connection.

You have several options here:

Use bridged networking: In this case, the virtual machine will be connected to the same network as the host computer, but with it’s own IP address etc.
NAT: In this case you will use the same IP address as the host. This is usefull, if you want to access the network and/or the internet, but don’t want to act as a standalone machine on the network.
Host-Only networking: Here you will have a separate network between the host computer and the virtual machine.
No network connection: Here you won’t have any network connection at all.

For the last step, you can configure the disk size which will be allocated to the virtual machine.

If done, you can still change the hardware settings for this virtual machine. Therefore, on the main screen of VMware, click on VM => Settings. You’ll find the following screen:

Here you should change the amount of memory, according to the memory installed on your host computer. Note that you have to share the available memory between the host computer and all running virtual machines.

For the CD-Rom, you can either use a real CD-Rom drive connected to the host pc or you use an existing ISO image of a CD. This works much faster and therefore I prefer this option.

If everything has been configured, you can start you virtual clicking on the following green button:

The virtual computer will start up and you can proceed with the installation of your operating system as usual. Afterwards, your machine is ready to get used. You can use it just like you are using you actual computer, with the difference that everything is virtual! If you hold on a second and think about the opportunities… there are many. It goes from testing, to extended security and much more

For those of you who are getting interested in the field of virtual computers and the VMWare products in special, we can recommend you the offical ‘VMWare Cookbook’, available in several online stores at fairly reasonable prices, just have a look yourself:

VMware Cookbook: A Real-World Guide to Effective VMware Use

Vmware Cookbook: A Real-World Guide to Effective Vmware Use

And, after all, if you hage additional doubts or questions, do not hesitate to leave a comment at the end of this article. We will be happy to receive your question and help you out.

Happy VMing!